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From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
To: Ulf Hansson <ulf.hansson@linaro.org>,
	Ludovic Barre <ludovic.Barre@st.com>
Cc: Rob Herring <robh+dt@kernel.org>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Alexandre Torgue <alexandre.torgue@st.com>,
	Benjamin Gaignard <benjamin.gaignard@linaro.org>,
	Gerald Baeza <gerald.baeza@st.com>,
	Loic Pallardy <loic.pallardy@st.com>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	DTML <devicetree@vger.kernel.org>,
	"linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
	linux-stm32@st-md-mailman.stormreply.com
Subject: Re: [PATCH V2 03/27] mmc: mmci: convert dma_setup callback to return an int
Date: Thu, 27 Sep 2018 09:55:05 +0100	[thread overview]
Message-ID: <55622e1c-190f-6903-ab04-16089264f277@linaro.org> (raw)
In-Reply-To: <CAPDyKFqnN0gg9WsbNPQcodqUXJmFEzMM+ST36s6oEZ2OPoONug@mail.gmail.com>

Thanks for looping me!

On 24/09/18 15:28, Ulf Hansson wrote:
>>   /* Initialize the dml hardware connected to SD Card controller */
>> -static void qcom_dma_setup(struct mmci_host *host)
>> +static int qcom_dma_setup(struct mmci_host *host)
>>   {
>>          u32 config;
>>          void __iomem *base;
>> @@ -131,7 +131,7 @@ static void qcom_dma_setup(struct mmci_host *host)
>>
>>          if (producer_id < 0 || consumer_id < 0) {
>>                  host->variant->qcom_dml = false;
> It seems like the existing code is an attempt to fallback to use pio
> mode. However, I doubt it works as is.

If I remember it correctly, Yes, that was the intent. we should still be 
able to use the pio mode if the dma setup fails.

I believe pio mode should work, Last time when I tried (3-4 years back) 
it did work!

> 
>> -               return;
>> +               return -EINVAL;
> My point is, if you return an error code here, it means that the error
> code becomes propagated and ->probe() will fail.
That would be very bad!, We should report it and may be just continue 
with pio mode.

> 
> Ideally, we should be able fall back to pio mode when dma doesn't
> work. I have looped in Srinivas who implemented the qcom dml support,
> let's see if he can explains the intent with the code.
> 
> I also volunteer to help out running some tests on the 410c platform,
I think you meant IFC6410.. DB410c uses sdhci.


--srini
> however allow me a day or two to do that.
> 

  parent reply	other threads:[~2018-09-27  8:55 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-21  9:45 [PATCH V2 00/27] mmc: mmci: add sdmmc variant for stm32 Ludovic Barre
2018-09-21  9:45 ` [PATCH V2 01/27] mmc: mmci: internalize dma map/unmap into mmci dma functions Ludovic Barre
2018-09-26 23:49   ` Ulf Hansson
2018-09-21  9:45 ` [PATCH V2 02/27] mmc: mmci: internalize dma_inprogress " Ludovic Barre
2018-09-26 23:49   ` Ulf Hansson
2018-09-21  9:45 ` [PATCH V2 03/27] mmc: mmci: convert dma_setup callback to return an int Ludovic Barre
2018-09-24 14:28   ` Ulf Hansson
2018-09-24 16:12     ` Ludovic BARRE
2018-09-26 23:49       ` Ulf Hansson
2018-09-27  8:55     ` Srinivas Kandagatla [this message]
2018-09-21  9:45 ` [PATCH V2 04/27] mmc: mmci: introduce dma_priv pointer to mmci_host Ludovic Barre
2018-09-24 18:52   ` Ulf Hansson
2018-09-25  7:19     ` Ludovic BARRE
2018-09-21  9:45 ` [PATCH V2 05/27] mmc: mmci: move mmci next cookie to mci host Ludovic Barre
2018-09-24 18:46   ` Ulf Hansson
2018-09-25  7:08     ` Ludovic BARRE
2018-09-21  9:46 ` [PATCH V2 06/27] mmc: mmci: merge prepare data functions Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 07/27] mmc: mmci: add prepare/unprepare_data callbacks Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 08/27] mmc: mmci: add get_next_data callback Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 09/27] mmc: mmci: modify dma_setup callback Ludovic Barre
2018-10-01  9:30   ` Ulf Hansson
2018-10-01  9:43     ` Ludovic BARRE
2018-09-21  9:46 ` [PATCH V2 10/27] mmc: mmci: add dma_release callback Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 11/27] mmc: mmci: add dma_start callback Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 12/27] mmc: mmci: add dma_finalize callback Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 13/27] mmc: mmci: add dma_error callback Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 14/27] mmc: mmci: add validate_data callback Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 15/27] mmc: mmci: add set_clk/pwrreg callbacks Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 16/27] mmc: mmci: add datactrl block size variant property Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 17/27] mmc: mmci: expand startbiterr to irqmask and error check Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 18/27] mmc: mmci: add variant properties to define cpsm & cmdresp bits Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 19/27] mmc: mmci: add variant property to define dpsm bit Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 20/27] mmc: mmci: add variant property to define irq pio mask Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 21/27] mmc: mmci: add variant property to write datactrl before command Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 22/27] mmc: mmci: add variant property to not read datacnt Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 23/27] mmc: mmci: add variant property to request a reset Ludovic Barre
2018-10-01  9:30   ` Ulf Hansson
2018-10-01 12:16     ` Ludovic BARRE
2018-10-01 13:43       ` Ulf Hansson
2018-09-21  9:46 ` [PATCH V2 24/27] mmc: mmci: add clock divider for stm32 sdmmc Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 25/27] mmc: mmci: add stm32 sdmmc registers Ludovic Barre
2018-09-21  9:46 ` [PATCH V2 26/27] mmc: mmci: add DT bindings for STM32 sdmmc Ludovic Barre
2018-09-25 15:27   ` Rob Herring
2018-10-01  9:30   ` Ulf Hansson
2018-09-21  9:46 ` [PATCH V2 27/27] mmc: mmci: add stm32 sdmmc variant Ludovic Barre
2018-10-01  9:31   ` Ulf Hansson
2018-10-01 12:56     ` Ludovic BARRE
2018-10-01 13:39       ` Ulf Hansson
2018-10-01 13:53         ` Ludovic BARRE
  -- strict thread matches above, loose matches on Subject: below --
2018-09-18 10:55 [PATCH V2 00/27] mmc: mmci: add sdmmc variant for stm32 Ludovic Barre
2018-09-18 10:55 ` [PATCH V2 03/27] mmc: mmci: convert dma_setup callback to return an int Ludovic Barre

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